Cartilage, particularly articular cartilage, of higher animals, including man, has a limited potential for repair. Following injuries to articular cartilage, the cartilage generally does not repair itself because of its limited capacity for regeneration. The ability to repair is dependent on the extent and the depth of injury and the surviving chondrocytes and normal articular cartilage matrix. In injuries involving subchondral bone, there is no regeneration of the cartilage, but there is typically enlargement and progression of the lesion with associated pain. The ultimate goal of treatment of these lesions is restoration of the cartilage, but in most cases this is not achieved.
Adult articular cartilage is not vascularized and, as stated above, lacks the capacity to regenerate itself after sustaining damage (Vangness, C. T., Jr. et al., Am. J. Orth. 33, No. 25S: 29, 2004). When cartilage is cut, without involvement of subchondral bone, the defect often will persist for the duration of the individual's life.
Treatment of articular cartilage defects may be either surgical or non-surgical. For example, several operative procedures are currently used to repair or remove damaged cartilage in order to prevent further destruction of the joint, decrease pain, and restore function. These include arthroscopic debridement and lavage, subchondral bone stimulating procedures, transplantation of chondrocytes or cartilage autografts and allografts and total knee arthroplasty. However, none of these produces regeneration of the native articular cartilage.
Thus, there is a desire for materials and methods for stimulating chondrogenesis.